A nickel hydroxide powder is used as a cathode active material for a nickel cadmium (Ni—Cd) battery and a nickel metal hydride (Ni-MH) battery. The nickel hydroxide powder is also used as a material for producing a lithium nickel oxide cathode active material of lithium-ion secondary battery.
Such secondary batteries are required to be down sized and enhance the capacity thereof. The cathode active materials (nickel hydroxide, lithium nickel oxide) are desired to be packed in high density in view of down-sizing the batteries and enhancing the capacity thereof, therefore a nickel hydroxide powder with a high tap density is required.